2 0 0 9 | W e s t e r g a s f a b r i e k | A m s t e r d a m | http://eComm.ec

LTE:

Long Term Employment

LTE: Long Term Employment or Less Than Expected?Moray Rumney

28th October 2009

Or

Less Than Expected?

Moray RumneyAgilent Technologies

© Copyright 2009 Agilent Technologies, Inc.

�

Opening thoughts

4G – Too little too soon?

Six concerns about the evolution of wireless:

1. Pursuit of high performance is not keeping up with demand

2. Growing complexity

3. Evidence of diminishing network quality

4. Market and supply chain fragmentation

LTE: Long Term Employment or Less Than Expected?Moray Rumney

28th October 2009

4. Market and supply chain fragmentation

5. Growing costs

6. Immature market – confusion over role of value, price and cost

Inspired by:

Technology in the Recession: Less is Moore

http://www.economist.com/opinion/displaystory.cfm?story_id=12932356

Page 2

Predicting the next winning technologyOften the “best” doesn’t win

• Ethernet vs. Token ring

• 802.11b vs. HiperLAN

• Windows 3.1 vs. Unix

• Iridium vs. GSM

• Esperanto vs. English (or maybe Chinese...)

LTE: Long Term Employment or Less Than Expected?Moray Rumney

28th October 2009

• Esperanto vs. English (or maybe Chinese...)

• Now it’s LTE vs. GSM, HSPA - and Wi-Fi

“Perfection is the enemy of the good”Gustave Flaubert

French Novelist 1821 - 1880

Page 3

What we would like in wireless…

Simplicity and economies of scale:

- One worldwide wireless standard for everything

- One air interface

- One frequency band

- One core network

LTE: Long Term Employment or Less Than Expected?Moray Rumney

28th October 2009

- One application development framework

- And no IPR (that we don’t own…)

For 2G, GSM substantially achieved this in 1992

For 3G, UMTS tried to achieve this in 1999 but faltered

For 4G, what is the outlook - will LTE deliver?

Page 4

Attractive attributes of LTE

Based on OFDMA giving:

• Scalable bandwidths for deployment flexibility and high data

rates

• Suitable for use with MIMO

• Supports narrowband scheduling to take advantage of fading

LTE: Long Term Employment or Less Than Expected?Moray Rumney

28th October 2009

• Potential for higher efficiency than CDMA at wide bandwidths

• Supports enhanced broadcast features (MBSFN)

• Support for in-channel relaying (backhaul)

Simpler low latency packet-only core network

Support for QoS (e.g. for VoIP)

Page 5

Planned Order

LTE: Long Term Employment or Less Than Expected?Moray Rumney

28th October 2009Page 6

…and the space (spectrum) to deploy it

Note use of spacial diversity!

LTE: Long Term Employment or Less Than Expected?Moray Rumney

28th October 2009Page 7

Denver

But what we have…

LTE: Long Term Employment or Less Than Expected?Moray Rumney

28th October 2009Page 8

…is the legacy

LTE: Long Term Employment or Less Than Expected?Moray Rumney

28th October 2009Page 9

5G 2G

3G

1G

Yuck!

LTE: Long Term Employment or Less Than Expected?Moray Rumney

28th October 2009Page 10

4G

Heathrow

IS-136TDMA PDCGSM

IS-95Acdma

Wireless evolution 1990 - 2010

2G

Incre

asin

g e

ffic

ien

cy,

ban

dw

idth

an

d d

ata

rate

s

2.5G

3G

HSCSD iModeGPRSIS-95Bcdma

E-GPRSEDGE

IS-95Ccdma2000

W-CDMAFDD

W-CDMATDD

TD-SCDMALCR-TDD

802.11g

802.11a

802.11b

802.11n

802.11h

LTE: Long Term Employment or Less Than Expected?Moray Rumney

28th October 2009

Incre

asin

g e

ffic

ien

cy,

ban

dw

idth

an

d d

ata

rate

s

3.5G

3.9G

4G

LTE-Advanced Rel-10

802.16m

HSUPAFDD & TDD

1xEV-DORelease B

1xEV-DORelease A

1xEV-DORelease 0

HSDPAFDD & TDD

UMB LTERel-8

Edge Evolution HSPA+

802.16eMobile

WiMAXTM

802.16dFixed

WiMAXTM

WiBRO

Page 11

In 20 years of evolution why has so little

come off the plate?

Phases of Technology Adoption

1. StandardizationThe Committee

Room

2. RegulationThe Test House

3. PhysicsMaxwell’s

Place

4. CommerceThe Shopping

Mall

LTE: Long Term Employment or Less Than Expected?Moray Rumney

28th October 2009

Where engineers consume lots of

coffee while creating wireless law

Where products are put on trial to prove their conformance

Where electro-magnetic law determines if it actually works

Where commercial law determines whether anyone actually buys it

And then there was light…

Just because the industry invents a new standard does not mean success is guaranteed. What determines commercial success?

Page 12

Technology evolution - Audio

Over the last century, audio has evolved from wax through shellac, vinyl, metallic tape, to opto-mechanical discs and finally solid state silicon

At each new generation the user perceived benefits have been undeniable meaning earlier generations have largely been obsoleted.

LTE: Long Term Employment or Less Than Expected?Moray Rumney

28th October 2009Page 13

Technology evolution – Cellular

Commercial Cellular phone technology started in the 70s with expensive bulky and heavy products moving through the first true “handsets” and onto GSM and CDMA

So is the added value of new generations slowing down?

LTE: Long Term Employment or Less Than Expected?Moray Rumney

28th October 2009Page 14

Performance - Which is the best car?

$2,500 $1,500,000

LTE: Long Term Employment or Less Than Expected?Moray Rumney

28th October 2009Page 15

Answer: Both! It depends on the problem you are trying to solve

Page 15

Top end wireless is a bit like the top end automotive• It is undeniably real• But is it affordable?

LTE: Long Term Employment or Less Than Expected?Moray Rumney

28th October 2009

And once you have purchased it, where and how often can you really experience it?

Top Speed – 253 mph

1001 bhp

0 – 60 mph in 2.5 seconds

0 – 125 mph in 7.5 sec

0 – 250 mph in 16.7 sec

250 – 0 mph in 9.8 sec

At top speed, empties its fuel tank in 12 minutes!

LTE: Long Term Employment or Less Than Expected?Moray Rumney

28th October 2009Price: $ 1,500,000 (plus tax!)

If your supercar commute to work looks like this then you will have paid for peak performance but

you will experience average or poor performance

LTE: Long Term Employment or Less Than Expected?Moray Rumney

28th October 2009

Quiz #1 - High speed vs. high capacity

At what average speed does the capacity (i.e.

cars per hour) of this road reach its peak?

10 mph ?

40 mph ?

70 mph ?

This is counter-intuitive: High speed drives down capacity!

In wireless, high data rates consume disproportionately more resources and provide less coverage for fewer users –

LTE: Long Term Employment or Less Than Expected?Moray Rumney

28th October 2009

100 mph ?

1000 mph?

coverage for fewer users –overall capacity reduces.

Improving capacity through higher average speeds is plain hard work

In motoring terms, improving the average would require a whole new form of robotic control.

Page 19

So what really matters - Peak or Average?

LTE: Long Term Employment or Less Than Expected?Moray Rumney

28th October 2009Page 20

WoW! Now with predictive

results!

What is enabling the apparent exponential growth in wireless communications?

The capacity of a system to deliver services is defined by three

main factors:

• The bandwidth of the available radio spectrum – in MHz

• The efficient use of that spectrum – bits / second / hertz

• The number of cells – this equates to spectrum reuse

LTE: Long Term Employment or Less Than Expected?Moray Rumney

28th October 2009

Number of cells

Eff

icie

nc

y

Page 21

Growth to date dominated by increasing cell count

If we apply Cooper’s law over the last 50 years we are looking at a growth in wireless capacity of perhaps 1,000,000

Allocating this growth between the axes of capacity looks roughly like this:

1000

200010000

Growth has

LTE: Long Term Employment or Less Than Expected?Moray Rumney

28th October 2009

Gro

wth

fa

cto

r

1

10

100

1000

2025

Efficiency Spectrum No. of cells

Growth has

historically been

dominated by the

increase in the

number of cells

Page 22

Comparing wireless growth potential for the next decade

Gro

wth

po

ten

tia

l

10

100

100

LTE: Long Term Employment or Less Than Expected?Moray Rumney

28th October 2009

Gro

wth

po

ten

tia

l

1

32

Efficiency Spectrum No. of cells

Using current projections, the increase of cell numbers (spectrum

reuse) remains the dominant means of growing capacity

Page 23

Spectral Efficiency bits / sec / Hz

1

10

100

W-CDMA

HSDPA

1xEV-DO

LTE

802.16e

IS-95C

Growth in peak / average spectral efficiency by technology

Peak efficiency lies around this line

Average efficiency and hence capacitygrowth of deployed systems lags well behind and will level

LTE: Long Term Employment or Less Than Expected?Moray Rumney

28th October 2009

0.01

0.1

1980 1985 1990 1995 2000 2005 2010 2015

Average efficiency Peak efficiency

AMPS

GSM

GPRS

EDGE

1xEV-DO(A)EGPRS2 1/3

W-CDMA (R99)EGPRS 4/12 (R99)

HSDPA (R7)HSDPA (R5)

LTE target

EGPRS 1/3 (R99)

off due to inter-cell interference

Peak efficiency drives

up air interface cost &complexity

You pay for the peak but experience the

average

Page 24

Projecting ahead shows the gap between average and peak rates in a loaded cell will grow to 90x

Data rates x 100000

Efficiency x 87Spectrum x 13

�1100x capacity 10000000

100000000

1000000000

Peak rates Average Efficiency Spectrum Capacity

Efficiency, spectrum and capacity are normalized to single-band GSM in 1992 83 users/cell occupying 25 MHz @ 9.6 kbps

LTE: Long Term Employment or Less Than Expected?Moray Rumney

28th October 2009

A 90x gap will exist by 2015

10000

100000

1000000

1985 1990 1995 2000 2005 2010 2015

The average efficiency, spectrum and capacity plots are normalized

The outlook is that average efficiency and spectrum will fall further behind

peak rates

Page 25

And on a linear scale

500000000

600000000

700000000

800000000

900000000

1000000000

Peak rates Average Efficiency Spectrum Capacity

Macrocell reality lies

somewhere below this line

The capacity crunch

LTE: Long Term Employment or Less Than Expected?Moray Rumney

28th October 2009

0

100000000

200000000

300000000

400000000

500000000

1985 1990 1995 2000 2005 2010 2015

below this line

Page 26

LTE: Long Term Employment or Less Than Expected?Moray Rumney

28th October 2009Page 27

Setting performance expectations –

150 Mbps is your right!

Examples of growing complexity:Voice support

2G & 3G

• Single solution – circuit-switched services

3.9G/4G LTE

1. IMS – preferred 3GPP solution

LTE: Long Term Employment or Less Than Expected?Moray Rumney

28th October 2009

1. IMS – preferred 3GPP solution

2. Circuit-Switched Fallback – preferred 3GPP alternative

3. VoLGA – UMA/GAN for LTE

4. Fast Track voice over LTE (NSN – SIP-based)

5. Proprietary solutions (e.g. Skype)

Choice creates unwanted interworking complexity

Page 28

IMT Band explosion

Operating Band

Uplink (UL) operating bandBS receive/UE transmit

Downlink (DL) operating bandBS transmit /UE receive

Duplex Mode

FUL_low – FUL_high FDL_low – FDL_high

1 1920 MHz – 1980 MHz 2110 MHz – 2170 MHz FDD

2 1850 MHz – 1910 MHz 1930 MHz – 1990 MHz FDD

3 1710 MHz – 1785 MHz 1805 MHz – 1880 MHz FDD

4 1710 MHz – 1755 MHz 2110 MHz – 2155 MHz FDD

5 824 MHz – 849 MHz 869 MHz – 894MHz FDD

6 830 MHz- – 840 MHz- 865 MHz – 875 MHz- FDD

7 2500 MHz – 2570 MHz 2620 MHz – 2690 MHz FDD

8 880 MHz – 915 MHz 925 MHz – 960 MHz FDD

9 1749.9 MHz – 1784.9 MHz 1844.9 MHz – 1879.9 MHz FDD

10 1710 MHz – 1770 MHz 2110 MHz – 2170 MHz FDD

11 1427.9 MHz – 1447.9 MHz 1475.9 MHz – 1495.9 MHz FDD

12 698 MHz – 716 MHz 728 MHz – 746 MHz FDD

13 777 MHz – 787 MHz 746 MHz – 756 MHz FDD

36.912 v9.0.0 Table 11.2.2-1 Operating bans for LTE-Advanced (E-UTRA operating bands)

Possible new bands

(a) 3.4-3.8 GHz band

(b) 3.4-3.6GHz as well as 3.6-4.2GHz

(c) 3.4-3.6 GHz band

(d) 450−470 MHz band,

(e) 698−862 MHz band

(f) 790−862 MHz ban

(g) 2.3−2.4 GHz band

(h) 4.4-4.99 GHz band

LTE: Long Term Employment or Less Than Expected?Moray Rumney

28th October 2009

13 777 MHz – 787 MHz 746 MHz – 756 MHz FDD

14 788 MHz – 798 MHz 758 MHz – 768 MHz FDD

15* 1900 MHz – 1920 MHz 2600 MHz – 2620 MHz FDD

16* 2010 MHz – 2025 MHz 2585 MHz – 2600 MHz FDD

17 704 MHz – 716 MHz 734 MHz – 746 MHz FDD

18 815 MHz – 830 MHz 860 MHz – 875 MHz FDD

19 830 MHz – 845 MHz 875 MHz – 890 MHz FDD

20 832 MHz – 862 MHz 791 MHz – 821 MHz FDD

21 1447.9 MHz – 1462.9 MHz 1495.9 MHz – 1510.9 MHz FDD

22 3410 MHz – 3500 MHz 3510 MHz 3600 MHz FDD

33 1900 MHz – 1920 MHz 1900 MHz – 1920 MHz TDD

34 2010 MHz – 2025 MHz 2010 MHz – 2025 MHz TDD

35 1850 MHz – 1910 MHz 1850 MHz – 1910 MHz TDD

36 1930 MHz – 1990 MHz 1930 MHz – 1990 MHz TDD

37 1910 MHz – 1930 MHz 1910 MHz – 1930 MHz TDD

38 2570 MHz – 2620 MHz 2570 MHz – 2620 MHz TDD

39 1880 MHz – 1920 MHz 1880 MHz – 1920 MHz TDD

40 2300 MHz – 2400 MHz 2300 MHz – 2400 MHz TDD

41 3400 MHz – 3600 MHz 3400 MHz – 3600 MHz TDD* Defined by ETSI for Europe only

Page 29

Baseline LTE FDD single band architecture

LTE: Long Term Employment or Less Than Expected?Moray Rumney

28th October 2009Page 30

Source: R4-091204 “Study of UE architectures for LTE-A deployment scenarios” Nokia

4G: Tri-band aggregation plus4x20 MHz contiguous operation

The Hedgehog PhoneTM

“An Antenna for every Occasion”

Supports up to:

• 19 frequency bands

LTE: Long Term Employment or Less Than Expected?Moray Rumney

28th October 2009Page 31

Source: (Excluding the hedgehog)

R4-091204 “Study of UE architectures

for LTE-A deployment scenarios” Nokia

• 19 frequency bands

• 8 simultaneous radio technologies

• 8x8 MIMO

Fan cooled –Blow dry your hair while you chat…

And for the geeks – A growing gap between conformance testing and real world operation

Attribute Conformance testing Real world operation

MIMO Correlation matrixHigh, medium and zero -

not linked to real antenna

Real correlation based on

actual antenna pattern

Fading channel Extended PA, VA, TU Channels with dynamic taps

Adaptive Modulation & coding

Off – UE becomes fading

channel discriminator

On – coding aims for constant

symbol to noise at UE receiver

CQI, PMI, RI Separate open loop tests Included as part of throughput

LTE: Long Term Employment or Less Than Expected?Moray Rumney

28th October 2009Page 32

CQI, PMI, RI Separate open loop tests Included as part of throughput

Cell-edge Interference signal

Static wideband

Gaussian

Narrowband frequency-

selective based on loading

Scheduling None, Single UE

Multiple UE, real scheduler with

frequency selectivity base on

subband CQI/PMI

Transmission mode FixedVariable based on prevailing

conditions

Over The Air (OTA) antenna testing

Probably open loopClosed loop with real loading /

scheduler / interference

Concern regarding baseline LTE Rel-8 performance

LTE Rel-8 targets were based on 2x to 4x gains over a limited version of Rel-6 HSPA

• Type 1 receiver – 16QAM Single stream with Rx diversity

A fair comparison would be with Rel-8 HSPA

• Type 3i receiver

• Add dual stream DL 2x2 MIMO

LTE: Long Term Employment or Less Than Expected?Moray Rumney

28th October 2009

• Add equalizer

• Add interference cancellation

• Add 64QAM

On paper the differences between Rel-8 HSPA and Rel-8 LTE are minimal –perhaps 20% in favour of LTE

In practise the advantage will be with the more mature HSPA and may stay that way

Page 33

OFDMA – An unproven cellular technology

Many benefits are expected from OFDMA

• Improved spectral efficiency

• Improved cell edge performance

• Better suited to MIMO

To date there are no commercial OFDMA deployments using 1x frequency reuse

LTE: Long Term Employment or Less Than Expected?Moray Rumney

28th October 2009

• Clearwire using 3x for suburban, 6x urban @ 2.6 GHz

• Single channel 10 MHz @ 700 MHz is a very different scenario

OFDMA Narrowband frequency-selective scheduling creates non-Gaussian cell-edge interference

• 3GPP simulations appear to have used the much easier Gaussian interference model which could inflate expectations

CDMA creates Gaussian interference which can be modelled and cancelled

Page 34

MIMO – An unproven cellular technology

Much has been said about MIMO for many years

We are still a long way from proving its effectiveness in typical

cellular environments

In particular the evaluation of MIMO OTA - Over The Air

• This is a radiated measurement that takes into account the all-

LTE: Long Term Employment or Less Than Expected?Moray Rumney

28th October 2009

important real antenna design

• Expect much angst and gnashing of teeth…

Page 35

Real life MIMO performance

Variation due to

instantaneous

correlation

Variation in the

frequency

This is what we

hear about :

2x gains

LTE: Long Term Employment or Less Than Expected?Moray Rumney

28th October 2009

Variation due to fading and variable interference

Most macrocell

activity takes

place in this

region

frequency

domain not

shown

Taking LTE MIMO from Standards to Starbucks

Moray Rumney 10th June 2009Page 36

Managing complexity is an exponential problem(and Moore is not the solution)

For n elements there are n2 - n possible interactions.

E.g. for 50 elements we have 2450 interactions…

Its not that systems can’t work it is primarily that as complexity rises there are just so many operational combinations to design and test for

LTE: Long Term Employment or Less Than Expected?Moray Rumney

28th October 2009

If 4 elements in a system are capable of interacting either in a

linear or complex fashion there are six

bi-directional scenarios to design and test for

But for a system with 9 elements, there are 36

bi-directional scenarios to consider

interactions…

Page 37

Conclusion:Interaction must

be minimized since we cannot

design or test quality into

complex systems

Looking ahead to the Cost/benefits of LTE-Advanced

Bandwidth Aggregation

Enhanced Uplink Higher order MIMO CoMP Relaying

Peak data rates

Spectral efficiency

Cell edge performance

LTE: Long Term Employment or Less Than Expected?Moray Rumney

28th October 2009

Coverage

UE cost

Network cost

Complexity (UE) (UE) (Network) (Network)

Page 38

The macrocellular dilemma

To deliver true mobile broadband these three attributes are all

required:

1. High data rates with the capacity and density to match

2. Ubiquitous coverage

3. Low or reasonable cost

LTE: Long Term Employment or Less Than Expected?Moray Rumney

28th October 2009

3. Low or reasonable cost

For macrocellular networks, pick any two!

Page 39

Conclusion: High efficiency macrocellular can’t do it alone.

Some form of small cells is essential.

Evidence of growing problems in the delivery of basic services

No time today for details but:

• Performance of MMS and video calls remain erratic

• SMS becoming less reliable

• Multiple receipts common

• Interworking with CDMA2000 still not figured out after more than a decade – multiple issues

LTE: Long Term Employment or Less Than Expected?Moray Rumney

28th October 2009

decade – multiple issues

• Network generated SMS spam

• Welcome to the Netherlands. What? Again!

• Voice connectivity problems between 2G/3G

• Caller ID frequently fails

Page 40

In a mature market, Value > price > cost

Price

Service

Data rate / volume

Price € Cost / MByte

Price / MByte

Relative price

SMS 160 Bytes €0.15 /

message€ X €1000 400,000

Voice 10 kbps €0.05 to €0.5 /

minute€ Y € 0.7 - € 7 300 - 3000

Data service

(capped at 3

3 GBytes €20 / month € Y/5 € 0.007 3

LTE: Long Term Employment or Less Than Expected?Moray Rumney

28th October 2009

(capped at 3

GBytes)

Unicast Mobile

TV (Capped at

50 hrs)

50 Hours

@ 100

kbps

€5 / month € Y/5 € 0.0023 1

Page 41

Cheap capacity generates unsustainable low value traffic

New air interfaces provide a linear solution to an exponential problem

FCC decision on Net Neutrality

“Broadband providers cannot discriminate against

services or applications by slowing them down”

For wireless, how does it look like from the other end?

LTE: Long Term Employment or Less Than Expected?Moray Rumney

28th October 2009

Stubbed toe of the decade perhaps?

Page 42

Is that the DoD? I’d like dad’s

newspaper delivered by helicopter please!No charge of course.

Key lessons learned from 20 years of cellular

What we learned from GSM (2G)Scale matters -> 4B devices worldwideUbiquitous low-rate services work and are hugely profitable (voice/SMS)

What we learned from UMTS (3G)A fat circuit-switched data pipe doesn’t cut itCoverage matters

What we learned from HSPA (3.5G)

LTE: Long Term Employment or Less Than Expected?Moray Rumney

28th October 2009

What we learned from HSPA (3.5G)Packet-switched data is essential for mobile broadbandWhen the megabits finally start flowing, data density mattersPricing data at 1% of voice is not sustainable

What we learned from the iPhoneUsability and apps are vastly more critical to innovation than air interfacesWi-Fi is an effective way to offload low-grade traffic from cellular

Page 43

What will it take for LTE to displace existing cellular to deliver on the unified vision?

Sufficient clean spectrum in which to gain a foothold (e.g.

European 800 MHz band)

Network optimization to milk opportunities and overcome

challenges with OFDM

Demonstrated performance to drive obsolescence of legacy and

evolving older technologies

LTE: Long Term Employment or Less Than Expected?Moray Rumney

28th October 2009

evolving older technologies

Solution to Voice support caused by the packet-only network

Proof that IMS is a viable solution for mobile systems

Economies of scale to drive down prices to below legacy

systems

Leave high volume / low value data to Wi-Fi and femtocells

Page 44

In pursuit of excellence

Could we improve on these?

LTE: Long Term Employment or Less Than Expected?Moray Rumney

28th October 2009Page 45

Surely!

But why don’t we?

The return is not worth the pain

The future of wireless is bright…but the future will have to be low cost/complexity

Would you like some nybble and bytes with that Sir?

iFi?

LTE: Long Term Employment or Less Than Expected?Moray Rumney

28th October 2009

iFi?

Page 46

Thank you for listening!

LTE: Long Term Employment or Less Than Expected?Moray Rumney

28th October 2009Page 47

Backup

LTE: Long Term Employment or Less Than Expected?Moray Rumney

28th October 2009Page 48

Geometry factor distribution in urban cellsC

um

ula

tive

dis

trib

uti

on

100 %

This plot shows the variation in geometry factor across a typical outdoor urban cell

Very high spectral efficiency is only seen when the geometry factor is above 15 dB, which is an environment that 90% of the user population will not

90% of users 10% of users

Most new high data rate/MIMO

performance targets require

geometry factors

LTE: Long Term Employment or Less Than Expected?Moray Rumney

28th October 2009

Geometry factor in dB

Cu

mu

lati

ve

dis

trib

uti

on

0 %

-30 30

that 90% of the user population will not experience

In-building penetration loss will degrade performance further

This puts a finite and very low limit on indoor performance when using outdoor transmission systems

0-20 -10 10 20

geometry factors experienced by

<10% of the user population

Page 49

In search of 21 Mbps

LTE: Long Term Employment or Less Than Expected?Moray Rumney

28th October 2009

Source:

Page 50

Example of interference-limited throughput*

HSDPA macrocell, single Rx + equalizer

15 code 64QAM, 20 Mbps peak

34 randomly distributed users

Quiz #2: What is the combined throughput and why?

M

M

MM

M

MM

M

M M

MM

M

M

MM

M

MM

M

MM

MM

MM

M

M

M

M

M

LTE: Long Term Employment or Less Than Expected?Moray Rumney

28th October 2009

20 Mbps

680 Mbps

13 Mbps

1.3 Mbps

M

MM

M M

* Source: 3GPP RAN WG4 R4-081344

Page 51

That is a median throughput of 40 kbps

(0.26 b/s/Hz)

Impact of femtocell deployment on throughput

Using the same macrocell add 96 femtocells

24 users migrate to femtocells

10 users remain on the macrocell

Quiz #3: What is the combined throughput and why?

M

M

MM

M

MM

M

M M

MM

M

M

MM

M

MM

M

MM

MM

MM

M

M

M

M

M

LTE: Long Term Employment or Less Than Expected?Moray Rumney

28th October 2009

27 Mbps

270 Mbps

2.7 Mbps

1.3 Mbps

That is an medianthroughput of 8 MbpsA 200x improvement!

The remaining macrocell users go from 50 kbps to 170 kbps

M

MM

M M

Page 52

CCDF of throughput with and without femtocells

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

CD

F

Co-Channel, Self Calibrated HNB Tx Power

24 HUEs + 10 MUEs/cell, 1 Rx

34 MUEs/cell, No HNBs, 1 Rx

40 kbps @

50 percentile0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

CD

F

Co-Channel, Self Calibrated HNB Tx Power

24 HUEs + 10 MUEs/cell, 1 Rx

34 MUEs/cell, No HNBs, 1 Rx

8 Mbps @

LTE: Long Term Employment or Less Than Expected?Moray Rumney

28th October 2009

0 1 2 3 4 5

x 105

0

0.1

0.2

All UEs Average Throughput (bps)

Detail showing 40 kbps median for macrocell

Projected spectrum and efficiency gains could push the blue trace to the right by 6x, this femtocell study moved it by 200x

0 2 4 6 8 10 12 14 16 18

x 106

0

0.1

0.2

All UEs Average Throughput (bps)

Full CCDF showing 8 Mbps median for

macrocell plus 24 active femtocells

8 Mbps @

50 percentile

Page 53

2 0 0 9 | W e s t e r g a s f a b r i e k | A m s t e r d a m | http://eComm.ec

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